Highlighter ink is conveniently used for visualization of blood vessels in chicken embryos. An E3.5 embryo was infused with violet ink, and Z-stack image with 240 slices of 10 µm each (=2,400 µm) was obtained by macroconfcal microscopy. Vascular networks covering both embryo proper and extraembryonic regions were visualized with a markedly high resolution. See Takase et al., 792–801.